Information processing apparatus, control method therefor, program, and recording medium

ABSTRACT

An information processing apparatus includes a touching detection unit configured to detect a touching operation and a touch-up operation for the display unit, a time counting unit configured to count a time period of continuous touching on a specific area of the display unit, and a control unit configured, when a touch-up operation from the specific area is detected and a counted time period of continuous touching has not reached a predetermined time period, to execute a function assigned to the specific area while when the touch-up operation from the specific area is detected and the counted time period of continuous touching has reached the predetermined time period, not to execute the function assigned to the specific area in relation only to the detected touch-up operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a division, and claims the benefit, of U.S.patent application Ser. No. 13/390,870, presently pending and filed Feb.16, 2012, which is a National Stage filing of PCT Application No.PCT/JP2010/004534 filed Jul. 13, 2010, which claims the benefit ofpriority from Japanese Patent Application No. 2009-189330 filed Aug. 18,2009, which applications are hereby incorporated by reference herein intheir entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an information processing apparatus anda control method therefor configured to prevent an operation error on atouch panel.

Description of the Related Art

In recent years, a digital device has been marketed that includes adisplay unit having a touch panel and allows a user to intuitivelyexecute an operation. A digital device like this generally allows a userto execute a function assigned to a button icon which is provided on adisplay screen including a touch panel by executing a “tapping”operation on the button icon.

A “tapping” operation on a button icon refers to an operation which canbe executed by only momentarily touching the button icon with a user'sfinger. Immediately after the user's finger is off the button icon, theuser operation is input and a function assigned to the button icon isexecuted.

A size of a body of a digital device having a touch panel has beenrecently decreased to achieve an advantage such that the total number ofparts of physical operation members can be reduced by providing a touchpanel. On the other hand, in order to improve the visibility, the sizeof the touch panel itself has become large.

If a ratio of an area of a touch panel to the size of the entire body ofthe device becomes large, then a hand of the user holding the devicebody may involuntarily touch a surface of the touch panel, which maycause an operation error. Various control methods for preventing anoperation error of a touch panel have been discussed as follows.

Japanese Patent Application Laid-Open No. 2009-009424 discusses a methodin which a touch panel includes an operation inhibited area. When a usertouches the operation inhibited area, the control method disables anoperation icon or displays a message indicating that the user hasexecuted a wrong operation. Accordingly, the control method allows theuser to recognize his/her operation mistake and prevents a wrong settingor an operation error.

Japanese Patent Application Laid-Open No. 05-298027 discusses a methodin which if a user continues touching a touch panel at the same locationfor a predetermined time period, then it is determined that a sensorelement for detecting a touching state of the touched position has beenmalfunctioning. In this case, the method disables an input executedafter that by touching the touch panel at the position.

However, because the method discussed in Japanese Patent ApplicationLaid-Open No. 2009-009424 includes the operation inhibited area, atouching operation member, such as an operable button icon, cannot beprovided in the operation inhibited area. More specifically, in thiscontrol method, a part of the entire area of a touch panel cannot beeffectively utilized. In addition, an arrangement and a layout oftouching operation members are restricted.

In the method discussed in Japanese Patent Application Laid-Open No.05-298027, even when a sensor element corresponding to a positiontouched by the user is normally functioning, if the user has actuallytouched the touch panel at the same position for a predetermined timeperiod or longer, then it is determined that the sensor element ismalfunctioning and the sensor element is disabled. Further, in thiscase, a touching operation executed after that is disabled. Accordingly,in this control method, a touching operation member, such as a buttonicon, cannot be provided at the position. More specifically, similar tothe case of the method discussed in Japanese Patent ApplicationLaid-Open No. 2009-009424, a part of the entire area of a touch panelcannot be effectively utilized and the arrangement and layout oftouching operation members are restricted.

SUMMARY OF THE INVENTION

The present invention is directed to an information processing apparatuscapable of securely suppressing an operation error on a touch panelwithout restricting a layout of touching operation members of the touchpanel.

According to an aspect of the present invention, an informationprocessing apparatus includes a touching detection unit configured todetect a touching operation for touching a display unit and a touch-upoperation, which is an operation for discontinuing the touching thedisplay unit, a time counting unit configured to count a time period ofcontinuous touching on a specific area of the display unit, and acontrol unit configured, when the touching detection unit detects that atouch-up operation on the display unit starting from the specific areain which the touching operation has been detected and if a time periodof continuous touching counted by the time counting unit has not reacheda predetermined time period, to execute a function assigned to thespecific area while when the touching detection unit detects that thetouch-up operation on the display unit from the specific area at whichthe touching operation has been detected and if the time period ofcontinuous touching counted by the time counting unit has reached thepredetermined time period, not to execute the function assigned to thespecific area in relation only to the detected touch-up operation.

According to an aspect of the present invention, an operation error on atouch panel can be securely suppressed without restricting a layout oftouching operation members on the touch panel.

Further features and aspects of the present invention will becomeapparent from the following detailed description of exemplaryembodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate exemplary embodiments, features,and aspects of the invention and, together with the description, serveto explain the principles of the present invention.

FIG. 1 illustrates an example of an external appearance and an exemplaryconfiguration of a digital camera.

FIG. 2 illustrates an example of a hardware configuration of a digitalcamera.

FIG. 3 illustrates an example of a state in which a user holds a digitalcamera.

FIG. 4 includes and refers to FIGS. 4A and 4B, where FIG. 4A is a formerpart of a flow chart illustrating an example of processing executedduring an image shooting mode.

FIG. 4B is a latter part of a flow chart illustrating an example ofprocessing executed during an image shooting mode.

FIG. 5 illustrates an example of an image shooting standby mode screendisplayed on a display unit.

FIG. 6 is a flow chart illustrating an example of processing executedwhen a switch 1 (SW1) is operated.

FIG. 7A illustrates an example of a display of a warning messagedisplayed on a display unit.

FIG. 7B illustrates an example of a display of a warning messagedisplayed on a display unit.

FIG. 8A illustrates an example of a method for detecting a single touchposition at which the user touches a resistance film type touch panel.

FIG. 8B illustrates an example of a method for detecting a single touchposition at which the user touches a resistance film type touch panel.

FIG. 8C illustrates an example of a method for detecting a plurality oftouch positions at which the user touches a resistance film type touchpanel.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the inventionwill be described in detail below with reference to the drawings.

FIG. 1 illustrates an example of an external appearance and an exemplaryconfiguration of a digital camera 100 which is an example of aninformation processing apparatus according to the present invention.

Referring to FIG. 1, a display unit 28 displays an image and variouspieces of information. On a surface of the display unit 28, a touchpanel which is an example of an operation unit 70 is provided. With thetouch panel, if a user touches the display unit 28, the touchingoperation by the user can be detected. With this configuration, a touchdetection unit according to an exemplary embodiment of the presentinvention is implemented.

A shutter button (a shutter operation member) 61 is an operation unitfor inputting an image shooting instruction. The operation unit 70includes an operation member for receiving various user operations, suchas various switches, buttons, and a panel.

The operation unit 70 includes a controller wheel 73. The controllerwheel 73 can be operated by the user by rotating it. In addition, theoperation unit 70 includes a zoom operation unit 71. The zoom operationunit 71 is an operation unit for switching to a zooming mode, such as anoptical zooming mode or an electronic zooming mode, during the imageshooting mode. Further, the zoom operation unit 71 switches theelectronic zooming and the number of images to be displayed during animage reproduction mode.

A connector 112 is a connector of the digital camera 100 to a connectioncable. A power switch 72 turns on and off power of the digital camera100. A recording medium 200 is a recording medium, such as a memory cardor a hard disk.

A recording medium slot 201 is a slot for storing the recording medium200. By inserting the recording medium 200 into the recording mediumslot 201, data can be transmitted to and from the recording medium 200and the digital camera 100. A lid 202 is a lid of the recording mediumslot 201.

FIG. 2 is a block diagram illustrating an exemplary hardwareconfiguration of the digital camera 100 according to a first exemplaryembodiment of the present invention.

Referring to FIG. 2, the digital camera 100 includes a photographic lens103 which includes a focus lens, a shutter 101 including an aperturestop function, and an image pickup unit 22, which includes an imagesensor, such as a charge-coupled device (CCD) or a complementary metaloxide semiconductor (CMOS), for converting an optical image into anelectrical signal.

An analog-to-digital (A/D) conversion device 23 converts an analogsignal into a digital signal. More specifically, the A/D conversiondevice 23 converts an analog signal output from the image pickup unit 22into a digital signal. A barrier 102 is provided to cover the imagepickup unit 22 including the photographic lens 103. The barrier 102prevents a smear and a damage of an image pickup system including thephotographic lens 103, the shutter 101, and the image pickup unit 22.

An image pickup unit 24 executes various image processing, such asresizing processing, including predetermined pixel interpolationprocessing, or color conversion processing, on data transmitted from theA/D conversion device 23 or loaded from a memory control unit 15.

In addition, the image pickup unit 24 executes predetermined calculationprocessing by using photographed image data. Furthermore, a systemcontrol circuit 50 executes exposure control and focus control accordingto a result of the calculation operation by the image pickup unit 24.Accordingly, through-the-lens (TTL) type auto focus (AF) processing,auto exposure (AE) processing, and electronic flash (EF) (pre-flashflashing) processing can be implemented.

Further, the image pickup unit 24 executes predetermined calculationprocessing by using photographed image data and executes TTL type autowhite balance (AWB) processing according to the result of thecalculation operation.

Data output from the A/D conversion device 23 is indirectly written on amemory 32 via the image pickup unit 24 and the memory control unit 15 ordirectly written on the memory 32 via the memory control unit 15.

The memory 32 stores data of an image taken by the image pickup unit 22and converted by the A/D conversion device 23 into digital data andimage data to be displayed on the display unit 28. The memory 32 has astorage capacity large enough to store a predetermined number of stillimages and a moving image and audio data of a predetermined time lengthof time. In addition, the memory 32 also functions as an image displaymemory (video memory).

A digital-to-analog (D/A) conversion device 13 converts image data to bedisplayed stored on the memory 32 into an analog signal. Further, theD/A conversion device 13 supplies the converted analog signal to thedisplay unit 28. The image data to be displayed written on the memory 32in the above described manner is then displayed on the display unit 28via the D/A conversion device 13. The display unit 28 displays the imagedata on a display device, such as a liquid crystal display (LCD),according to the analog signal from the D/A conversion device 13.

A non-volatile memory 56 is an electrically rewritable and recordablememory. Electrically erasable programmable ROM (EEPROM) is used as thenon-volatile memory 56. The non-volatile memory 56 stores a constant anda program used for operating the system control circuit 50. In thepresent invention, a “program” refers to a program used in executingvarious processing illustrated in flowcharts described below accordingto an exemplary embodiment of the present invention.

The system control circuit 50 is a control unit to controls an operationof the entire digital camera 100. By executing the program recorded onthe non-volatile memory 56, the system control circuit 50 implementseach processing according to the present exemplary embodiment which willbe described in detail below.

A system memory 52 includes a random access memory (RAM). The constantand the program used for operating the system control circuit 50, andprograms are read from the non-volatile memory 56 on the system memory52. Further, the system control unit controls the memory 32, the D/Aconversion device 13, and the display unit 28 to execute control ofdisplay.

A first shutter switch 62, a second shutter switch 64, and an operationunit 70 are an operation member operated by the user to input variousoperation instructions to the system control circuit 50.

When the shutter switch 62 (hereinafter simply referred to as an “SW1”)is half-pressed by the user, namely when an image shooting standbyinstruction is input by the user by pressing the shutter button 61 ofthe digital camera 100 halfway, the SW1 becomes ON and a first shutterswitch signal is generated. An operation of various processing, such asAF processing, AE processing, AWB processing, or EF processing, startsaccording to the first shutter switch signal.

When the second shutter switch 64 (hereinafter simply referred to as an“SW2”) is fully pressed by the user, namely when an image shootinginstruction is input by the user by completely operating the shutterbutton 61, the SW2 becomes ON and a second shutter switch signal isgenerated. The system control circuit 50 starts a series of operationsof image shooting processing from the reading of a signal output fromthe image pickup unit 22 to writing image data on the recording medium200.

A mode shift switch 60 is included in the operation unit 70. The modeshift switch 60 can be operated to give an instruction for shifting theoperation mode of the system control circuit 50 to either one of theimage shooting mode and the image reproduction mode.

In the present exemplary embodiment, the image shooting mode includesthe following plurality of modes, such as an auto image shooting mode, amanual mode, and a scene mode. In the auto image shooting mode, variousparameters for the digital camera 100 are automatically determined by aprogram installed on the digital camera 100 according to a detectedexposure value. In the manual mode, the user can freely change variousparameters set for the digital camera 100. In the scene mode, a shutterspeed, an aperture stop value, a flash emission state, and a sensitivitysetting are automatically set in combination. Further, the scene modeincludes various modes, such as a portrait mode, a nightscape mode, alandscape mode, a nightscape and snapshot mode, a kids and pet mode, afresh green and autumn color mode, a party shot mode, a snow mode, abeach mode, a fireworks mode, an aquarium mode, and an underwater mode.

Each operation member of the operation unit 70 is appropriately assignedwith a function corresponding to each scene by selecting and operatingvarious functional icons displayed on the display unit 28 and functionsas a function button. In the present exemplary embodiment, a functionbutton includes an end button, a return button, an image forward button,a jump button, a search narrow down button, and an attribute changebutton.

When the user presses a menu button, various menu screens for executingvarious settings are displayed on the display unit 28. The user canintuitively execute various settings via the menu screen displayed onthe display unit 28 with using physical buttons including afour-direction button and a SET button.

The controller wheel 73 is included in the operation unit 70 and can beoperated by the user by rotating it. The controller wheel 73 can beoperated in combination with each direction button to select a selectionitem.

More specifically, when the user operates the controller wheel 73 byrotating the same, an electrical pulse signal is generated according toan operation amount. The system control circuit 50 controls eachcomponent of the digital camera 100 according to the pulse signal. Anangle of rotation operation and the number of revolutions of thecontroller wheel 73 can be determined according to the pulse signal.

A type of the controller wheel 73 is not limited to a specific typewheel. Any operation member can be used as long as whose rotationoperation can be detected by the system control circuit 50. For example,it is also useful if a dial operation member is used as the controllerwheel 73 if a pulse signal is generated when the dial operation memberis rotated and operated. In addition, it is also useful if a touch wheelwhich is an operation member including a touch sensor can be used as thecontroller wheel 73. In this case, it is useful if the controller wheel73 itself does not rotate and a rotating movement of a finger of theuser on the controller wheel 73 is detected.

A power control unit 80 includes a battery cell detection circuit,direct current (DC)-DC converter, and a switch circuit. The switchcircuit switches a block to which power is supplied. The power controlunit 80 determines whether a battery cell has been mounted, a type ofthe mounted battery cell, and a remaining amount of the battery.

In addition, the power control unit 80 controls the DC-DC converteraccording to a result of the above described determination and aninstruction from the system control circuit 50. Further, the powercontrol unit 80 supplies necessary power voltage to each unit includingthe recording medium 200 for a necessary time period.

A power source unit 30 includes a primary battery, such as an alkalinecell and a lithium cell, a secondary battery, such as an NiCd cell, anNiMH cell, or an Li cell, and an alternate current (AC) adapter. Aninterface 18 is an interface with the recording medium 200, such as amemory card or a hard disk. The recording medium 200 is a recordingmedium such as a memory card and includes a semiconductor memory or amagnetic disk.

In addition, the operation unit 70 includes a touch panel capable ofdetecting a touching operation on the display unit 28 by a user. Thesystem control circuit 50 is capable of detecting the following useroperation on the touch panel. More specifically, the system controlcircuit 50 is capable of detecting a user operation for touching thetouch panel with his/her finger or a pen (hereinafter an operation ofthis type is simply referred to as a “touch-down operation”), a useroperation for continuing touching on the touch panel with his/her fingeror a pen (hereinafter an operation of this type is simply referred to asa “touch-on operation”), a user operation for moving on the touch panelwhile touching the touch panel with his/her finger (hereinafter anoperation of this type is simply referred to as a “move operation”), anda user operation for releasing the touching on the touch panel withhis/her finger or a pen (hereinafter an operation of this type is simplyreferred to as a “touch-up operation”) and a user non-operation state inwhich the user does not touch the touch panel (hereinafter this state issimply referred to as a “touch-off state”).

These operations and positional coordinates corresponding to a positionat which the user touches the touch panel with his/her finger or a penis notified to the system control circuit 50 via an internal bus 111.The system control circuit 50 determines what user operation has beenexecuted on the touch panel according to the notified information.

With respect to the moving operation, a direction of moving of theuser's finger or the pen moving on the touch panel can be determined inrelation to a longitudinal component and a lateral component on thesurface of the touch panel according to variation of the positionalcoordinates. When the user executes a touch-down operation, then apredetermined moving operation, and then a touch-up operation on thetouch panel, it is supposed that the user draws a stroke. In the presentexemplary embodiment, an operation for quickly drawing a stroke isreferred to as a flick operation.

The flick operation is an operation in which the user quickly moveshis/her finger by a specific distance on the touch panel while touchingthereon, and then releasing his/her finger from the touch panel. Inother words, the flick operation is an operation for sweeping the touchpanel like filliping.

If a moving operation for a predetermined distance or longer at apredetermined operation speed or higher is detected and then a touch-upoperation is detected in this state, then the system control circuit 50determines that the user has executed a flick operation. On the otherhand, if a moving operation for a predetermined distance or longer at aspeed lower than the predetermined operation speed is detected, then thesystem control circuit 50 determines that the user has executed a dragoperation.

Now, an exemplary operation executed according to the present exemplaryembodiment will be described in detail below with reference to FIGS. 3through 8.

In the present exemplary embodiment, if a touch-on operation in a buttonicon area of the touch panel for a predetermined time period isdetected, the system control circuit 50 executes control not forenabling (executing) a function of the button icon that the user hastouched even when the user executes a touch-up operation after that. Thepresent exemplary embodiment executes the above described controlbecause, if a touch-on operation of the button icon for a predeterminedtime period or longer is detected, it is determined that the user doesnot desire to operate the button icon.

FIG. 3 illustrates an example of a state in which the user holds thedigital camera 100 with one hand. Referring to FIG. 3, suppose that theuser desires to take an image in the image shooting mode. In most caseslike this the user, in order to operate the shutter button 61 or thezoom operation unit 71 with an index finger 301 of a right hand (adominant hand) of the user, holds the digital camera 100 in a stateillustrated in FIG. 3, in which the right hand index finger 301 istouching a portion close to the shutter button 61 or the zoom operationunit 71. In this case, a right hand thumb 302 may naturally touch thedisplay unit 28 which is the touch panel although the user does notintentionally touch the display unit 28 to operate the touch panel. Inthis state, if a button icon is provided at a position at which the userunintentionally touches the touch panel with the right hand thumb 302,then the function of the button icon may be executed when the userreleases the right hand thumb 302 from the digital camera 100 even ifthe user does not intend to operate the button icon. In other words, anoperation error described above may occur in this case.

In the present exemplary embodiment, if a touch-on operation for apredetermined time period or longer at the position at which the buttonicon is provided is detected, then it is determined that the user hasmerely held the digital camera 100 with unintentionally touching thetouch panel as illustrated in FIG. 3. Further, in this case, the presentexemplary embodiment does not execute the function of the button iconeven if the user executes a touch-up operation after that.

FIG. 4, which includes and refers to FIGS. 4A and 4B, is a flow chartillustrating an example of processing executed by the system controlcircuit 50 in the image shooting mode. Each processing according to theflow chart in FIGS. 4A and 4B is implemented by the system controlcircuit 50 by loading a program from the non-volatile memory 56 on thesystem memory 52 and executing it.

When the digital camera 100 is activated in the image shooting mode orwhen the digital camera 100 is activated in another operation mode, suchas the image reproduction mode, and shifted to the image shooting modeby the user operation of the mode shift switch 60 of the operation unit70, the processing illustrated in FIGS. 4A and 4B starts.

Referring to FIG. 4A, in step S401, the system control circuit 50displays an image shooting standby screen. FIG. 5 illustrates an exampleof an image shooting standby screen displayed on the display unit 28.Referring to FIG. 5, the display unit 28 displays a through-the-lensimage 500, which is an image taken real time by the image pickup unit22. Each of button icons 501 through 503 is a button icon whose functionis executed when the user taps on the corresponding button icon. Each ofthe button icons 501 through 503 corresponds to the content of acurrently setting used in image taking by the digital camera 100.

More specifically, the button icon 501 is a mode switching button. Theuser can change the setting to a desired image shooting mode which isselected from among a plurality of image shooting modes by tapping onthe button icon 501. In the example illustrated in FIG. 5, it issupposed that the user has set the portrait mode (one of the pluralityof scene modes), of the plurality of image shooting modes.

The button icon 502 is a flash setting button. The user can change thesetting of the flash by tapping on the button icon 502. In the exampleillustrated in FIG. 5, it is supposed that inhibition of the flash hasbeen currently set.

The button icon 503 is an exposure correction button. The user cancorrect the exposure by tapping on the button icon 503. In the exampleillustrated in FIG. 5, the setting “plus or minus 0” has been currentlyset for the exposure correction.

An icon 504 indicates a current attitude of the digital camera 100. Anicon 505 indicates the currently remaining amount of the battery. Anicon 506 indicates information about the number of remaining stillimages recordable on the recording medium 200 according to the currentsetting. An icon 507 indicates a currently setting of the number ofpixels to be recorded and a currently set setting of a compression rate.

Returning to FIG. 4A, after displaying the image shooting standby screenin step S401, the processing advances to step S402. In step S402, thesystem control circuit 50 determines whether the user has been touchingthe button icon 501.

When the user executes a touch-down operation with his/her finger at theposition of the button icon 501 or when the user has moved his/herfinger from a different other position to the position of the buttonicon 501 in a touch-on state, then the system control circuit 50determines that the user has been touching the button icon 501. If it isdetermined that the user has been touching the button icon 501 (Yes instep S402), then the processing advances to step S408. On the otherhand, if it is determined that the user is not currently touching thebutton icon 501 (No in step

S402), then the processing advances to step S403.

In step S403, the system control circuit 50 determines whether the userhas been touching the button icon 502. In the present exemplaryembodiment, if the user executes the touch-down operation at theposition of the button icon 502 or if the user moves his/her finger froma different other position to the position of the button icon 502 in thetouch-on state, then the system control circuit 50 determines that theuser has been touching the button icon 502.

If it is determined that the user has been touching the button icon 502(Yes in step S403), then the processing advances to step S404. On theother hand, if it is determined that the user is not currently touchingthe button icon 502 (No in step S403), then the processing advances tostep S436.

In step S404, the system control circuit 50 determines whether theposition of touching (hereinafter simply referred to as a “touchingposition”) has moved outside the area of the button icon 502. If it isdetermined that the touching position has moved outside the area of thebutton icon 502 (Yes in step S404), then the processing advances to stepS436. On the other hand, if it is determined that the touching positionhas not moved outside the area of the button icon 502 (No in step S404),then the processing advances to step S405. In step S405, the systemcontrol circuit 50 determines whether the SW1 is ON. If it is determinedthat the SW1 is ON (Yes in step S405), and then the processing advancesto step S601 illustrated in FIG. 6. Processing according to the flowchart in FIG. 6 will be described in detail below.

On the other hand, if it is determined that the SW1 is not ON (No instep S405), then the processing advances to step S406. In step S406, thesystem control circuit 50 determines whether the user has executed thetouch-up operation from the position of the button icon 502. If it isdetermined that the user has executed the touch-up operation from theposition of the button icon 502 (Yes in step S405), then the processingadvances to step S407. On the other hand, if it is determined that theuser has not executed the touch-up operation from the position of thebutton icon 502 (No in step S405), then the processing returns to stepS404.

In step S407, the system control circuit 50 executes a function assignedto the button icon 502. More specifically, in the example illustrated inFIG. 5, a function for switching the setting of the flash has beenassigned. Accordingly, in step S407, the system control circuit 50executes control for switching the flash setting in this case. Afterexecuting the function of the button icon 502, the processing advancesto step S436.

In step S408, which is processing executed if it is determined that theuser has been touching the button icon 501, the system control circuit50 starts a timer for counting the time period during which the usercontinues the touch-on state of the button icon 501.

In step S409, the system control circuit 50 determines whether thetouching position has moved outside the area of the button icon 501. Ifit is determined that the touching position has moved outside an area ofthe button icon 501 (Yes in step S409), then the processing advances tostep S410. In step S410, the system control circuit 50 stops the timerstarted in step S408 and clears the count of the timer. Then, theprocessing returns to step S402.

On the other hand, if it is determined that the touching position hasnot moved outside the area of the button icon 501 (No in step S409),then the processing advances to step S411. In step S411, the systemcontrol circuit 50 determines whether the count of the timer started instep S408 has reached a predetermined time period. More specifically, instep S411, the system control circuit 50 determines whether the touchingoperation of the button icon 501 has continued for the predeterminedtime period or longer. In other words, the predetermined time period isused for determining whether the user has intended to tap the buttonicon 501 (to “tap” refers to an operation for executing a touch-upoperation immediately after executing a touch-down operation). In thepresent exemplary embodiment, it is supposed that the predetermined timeperiod is set to 300 msec.

If it is determined that the touching operation of the button icon 501has continued for the predetermined time period or longer (Yes in stepS411), then the processing advances to step S416. On the other hand, ifit is determined that the touching operation of the button icon 501 hasnot reached the predetermined time (No in step S411), then theprocessing advances to step S412.

In step S412, the system control circuit 50 determines whether the SW1is ON. If it is determined that the SW1 is ON (Yes in step S412), thenthe processing advances to step S601 illustrated in FIG. 6. Processingaccording to the flow chart in FIG. 6 will be described in detail below.

On the other hand, if it is determined that the SW1 is not ON (NO instep S412), then the processing advances to step S413. In step S413, thesystem control circuit 50 determines whether the user has executed atouch-up operation. The processing in step S413 implements a touch-upoperation detection unit according to the present exemplary embodiment.More specifically, if the user has executed the touch-up operation fromthe position of the button icon 501 within the predetermined time periodafter the user started touching the button icon 501, then the systemcontrol circuit 50 determines that the user has executed the touch-upoperation.

If it is determined that the user has executed the touch-up operation(Yes in step S413), then the processing advances to step S414. On theother hand, if it is determined that the user has not executed thetouch-up operation (No in step S413), then the processing returns tostep S409.

In step S414, the system control circuit 50 stops the timer started instep S408 and clears the count of the timer. In step S415, the systemcontrol circuit 50 executes a function assigned to the button icon 501.In the example illustrated in FIG. 5, a function for switching the imageshooting mode is assigned to the button icon 501. Accordingly, in thiscase, the system control circuit 50 executes the function for changingthe setting to the desired image shooting mode which is selected fromamong the plurality of image shooting modes. After executing thefunction assigned to the button icon 501 in step S415, the processingadvances to step S436.

In step S416, the system control circuit 50 stops the timer started instep S408 and clears the count of the timer. In step S417, according tothe determination such that the time of continuously touching the buttonicon 501 has reached the predetermined time period, the system controlcircuit 50 determines that the user has not intended to execute anoperation for tapping the button icon 501 and displays a warning message1 (a first warning message display).

FIG. 7A illustrates an example of the warning message 1. FIG. 7Aillustrates an upper-right corner of the display unit 28 when thedigital camera 100, in which the image shooting standby screenillustrated in FIG. 5 is currently displayed, is held in the mannerillustrated in FIG. 3. In the example illustrated in FIG. 7A, the thumbof the user is unintentionally touching the button icon 501. Further, ithas been determined that the button icon 501 is in a touch-on state forthe predetermined time period or longer in step S411 in FIG. 4A.Accordingly, the system control circuit 50 displays a warning message 1701.

The warning message 1 701 indicates, to the user, that the user has beencontinuously touching the button icon 501 and that the function of thebutton icon 501 is not to be executed if the user releases his/her thumbfrom the button icon 501, as will be described in detail below. Bydisplaying the warning message 1 701 to the user, the present exemplaryembodiment can prevent the user from misunderstanding that if thefunction is not executed when the user has executed the touch-upoperation, the touch-up operation is not executed due to a malfunctionof the digital camera 100. It is also useful if the display of thebutton icon 501 is changed to a “button-down” display which indicatesthat the button icon 501 has been pressed when the touching of thebutton icon 501 by the user is detected. In this case, the button-downdisplay may be discontinued at a timing of displaying the warningmessage 1.

In addition, it is also useful if it is determined that the button icon501 is in the touch-on state for the predetermined time period or longerin step S411, then the system control circuit 50 discontinues thebutton-down display of the button icon 501 and merely returns thedisplay of the button icon 501 to its original display state withoutdisplaying the warning message 1. Further, by merely discontinuing thebutton-down display of the button icon 501, it can be indicated to theuser that the function of the button icon 501 is not to be executed ifthe user releases his/her finger from the button icon 501 from the abovedescribed state.

After executing the processing in step S417 in FIG. 4B, the processingadvances to step S418. In step S418, the system control circuit 50determines whether the SW1 is ON. If it is determined that the SW1 is ON(Yes in step S418), then the processing advances to step S419. In stepS419, the system control circuit 50 clears (ends) the display of thewarning message 1. Then, the processing advances to step S601 in FIG. 6.Processing according to the flow chart in FIG. 6 will be described indetail below.

On the other hand, if it is determined that the SW1 is not ON (No instep S418), then the processing advances to step S420. In step S420, thesystem control circuit 50 determines whether the user has executed anoperation of the operation member of the operation unit 70 other thanthe touch panel, such as the physical button. If it is determined thatthe user has executed an operation of the operation member other thanthe touch panel (Yes in step S420), then the processing advances to stepS421. On the other hand, if it is determined that the user has notexecuted an operation of the operation member other than the touch panel(No in step S420), then the processing advances to step S423.

In step S421, the system control circuit 50 clears (ends) the display ofthe warning message 1. In step S422, the system control circuit 50executes processing corresponding the operation member which isdetermined to have been operated in step S420. More specifically, if theuser operates the operation member other than the touch panel whilecontinuously touching the button icon 501, the operation of the otheroperation member is prioritized. Accordingly, the warning message 1,which is a warning message related to the button icon 501, is cleared.After executing the processing in step S422, then the processing returnsto step S402.

In step S423, the system control circuit 50 determines whether the userhas touched the touch panel at another position with another fingerwhile touching the button icon 501. The processing in step S423implements a multi-point touch determination unit according to thepresent exemplary embodiment. The determination processing in step S423will be described in detail below with reference to FIG. 8.

If it is determined that the user has touched the touch panel at adifferent other position (Yes in step S423), then the processingadvances to step S426. On the other hand, if it is determined that theuser has not touched the touch panel at the different other position (Noin step S423), then the processing advances to step S424.

In step S424, the system control circuit 50 determines whether thetouching position has moved outside the area of the button icon 501. Ifit is determined that the touching position has moved outside the areaof the button icon 501 (Yes in step S424), then the processing advancesto step S435. On the other hand, if it is determined that the touchingposition has not moved outside the area of the button icon 501 (No instep S424), then the processing advances to step S425.

In step S425, the system control circuit 50 determines whether the userhas executed a touch-up operation. The processing in step S425implements a touch-up operation determination unit according to thepresent exemplary embodiment.

If it is determined that the user has executed the touch-up operation(Yes in step S425), then the processing advances to step S435. On theother hand, if it is determined that the user has not executed thetouch-up operation (No in step S425), then the processing returns tostep S418. The touch-up operation described here is that the user hasexecuted the touch-up operation from the position of the button icon 501after the touch-on state for the predetermined time period or longer onthe button icon 501 is detected. When the system control circuit 50determines that the user has executed the touch-up operation in thismanner, the function assigned to the button icon 501 is not executed. Inother words, if the predetermined time period has elapsed while the userhas been continuously touching the button icon 501, then the button icon501 is temporarily disabled. In this case, if the user executes thetouch-up operation on the button icon 501, the system control circuit 50does not execute the function assigned to the button icon 501 (i.e., theswitching of the image shooting mode).

In step S426, the system control circuit 50 displays a warning message 2(a second warning message) in addition to the warning message 1. FIG. 7Billustrates an example of a display of the warning message 2. In FIG.7B, an example of a state is illustrated in which the user holds thedigital camera 100, which is currently displaying the image shootingstandby screen illustrated in FIG. 5 in the manner described above withreference to FIG. 3. In addition, it is supposed that the user hastouched the touch panel at another position with another finger. In thiscase, the user may intend to execute an operation on the touch panelwith the other finger without knowing that he/she has been touching thebutton icon 501 with the right hand thumb. Further, in this case,because the touching of the button icon 501 has been detected earlier,the system control circuit 50 cannot accept the user operation with theother finger. Accordingly, in this case, the system control circuit 50displays a warning message 2 702, which indicates that the operationwith the other finger cannot be executed.

In the present exemplary embodiment, the touching operation other thanthe operation via the button icon 501 includes tapping on the buttonicon 502 or 503 and a “touch AF operation”. In the present exemplaryembodiment, the “touch AF operation” is an operation corresponding to afunction for adjusting a focus to an arbitrary object touched on thescreen, selected from the through-the-lens image 500 displayed on thedisplay unit 28. The touch AF operation cannot be executed when thebutton icon 501 has been touched. Accordingly, in the exampleillustrated in FIG. 7B, the warning message 2 702 indicates that thetouch AF function cannot be executed. In the present exemplaryembodiment, it is supposed that the warning message 2 702 issuperposedly displayed in a display state in which the warning message 1701 is superposedly displayed on the image shooting standby screenillustrated in FIG. 5, which is displayed on the display unit 28. Morespecifically, although not illustrated in FIG. 7B, it is supposed thatthe icons 504 through 507 and black side margin areas are displayed inthis case.

After step S426, the processing advances to step S427. In step S427, thesystem control circuit 50 determines whether the SW1 is ON. If it isdetermined that the SW1 is ON (Yes in step S427), then the processingadvances to step S428. In step S428, the system control circuit 50clears (ends) the display of the warning messages 1 and 2. Then, theprocessing advances to step S601 in FIG. 6. Processing according to theflow chart in FIG. 6 will be described in detail below.

On the other hand, if it is determined that the SW1 is not ON (No instep S427), then the processing advances to step S429. In step S429, thesystem control circuit 50 determines whether the user has executed anoperation of the operation member of the operation unit 70 other thanthe touch panel, such as the physical button. If it is determined thatthe user has executed an operation of the operation member other thanthe touch panel (Yes in step S429), then the processing advances to stepS430. On the other hand, if it is determined that the user has notexecuted an operation of the operation member other than the touch panel(No in step S429), then the processing advances to step S432.

In step S430, the system control circuit 50 clears (ends) the display ofthe warning messages 1 and 2. In step S431, the system control circuit50 executes processing corresponding the operation member which isdetermined to have been operated in step S429. After executing theprocessing in step S431, the processing returns to step S402.

In step S432, the system control circuit 50 determines whether the userhas executed the touch-up operation at a position different from theposition which is determined in step S423 that the user has beentouching. If it is determined that the touch-up operation at thedifferent other position has not been executed (No in step S432), thenthe processing returns to step S427. On the other hand, if it isdetermined that the touch-up operation at the different other positionhas been executed (Yes in step S432), then the processing advances tostep S433.

In step S433, the system control circuit 50 clears the display of thewarning message 2 while continuing the display of the warning message 1.In step S434, the system control circuit 50 determines whether the usercontinuously touching the button icon 501 in the touch-on state. If itis determined that the user continuously touching the button icon 501 inthe touch-on state (Yes in step S434), then the processing returns tostep S418. On the other hand, if it is determined that the user is notcurrently touching the button icon 501 (No in step S434), then theprocessing advances to step S435. More specifically, in the presentexemplary embodiment, the system control circuit 50 determines that theuser is not currently touching the button icon 501 if the user has movedhis/her finger outside the area of the button icon 501 or executed thetouch-up operation while touching the touch panel at a different otherposition with the different other finger. However, in this case, similarto the touch-up operation in step S425, because the touch-on state ofthe button icon 501 has already continued for the predetermined timeperiod or longer, the button icon 501 is temporarily disabled.Accordingly, the system control circuit 50 does not execute the functionof the button icon 501.

In step S435, the system control circuit 50 clears the display of thewarning message 1. In step S436, the system control circuit 50determines whether the SW1 is ON. If it is determined that the SW1 is ON(Yes in step S436), then the processing advances to step S601 (FIG. 6).Processing according to the flow chart in FIG. 6 will be described indetail below. On the other hand, if it is determined that the SW1 is notON (No in step S436), then the processing advances to step S437.

In step S437, the system control circuit 50 determines whether adifferent other operation has been executed by the user. In the presentexemplary embodiment, the different other operation includes anoperation of the operation member of the operation unit 70 other thanthe touch panel, and an operation on the touch panel at a position otherthan the position of the button icon 501 or the button icon 502 (forexample, an operation of the button icon 503 or above described touch AFoperation). If it is determined that the user has executed the differentother operation (Yes in step S437), then the processing advances to stepS438. In step S438, the system control circuit 50 executes processingaccording to the different other operation. Then, the processingadvances to step S439. On the other hand, if it is determined that theuser has not executed any different other operation (No in step S437),then the processing advances to step S439.

In step S439, the system control circuit 50 determines whether the userhas executed an image shooting end operation. In the present exemplaryembodiment, the “image shooting end operation” refers to an operationfor switching to a mode other than the image shooting mode (i.e., to theimage reproduction mode) by operating the mode shift switch 60, or anoperation for turning off the power of the digital camera 100 byoperating the power switch 72. If it is determined that the user has notexecuted the image shooting end operation (No in step S439), then theprocessing returns to step S402. On the other hand, if it is determinedthat the user has executed the image shooting end operation (Yes in stepS439), then the processing in the image shooting mode ends.

FIG. 6 is a flow chart illustrating an example of processing executedwhen it is determined that the SW1 is ON during the processing in theimage shooting mode, which is described above with reference to FIGS. 4Aand 4B. Each processing according to the flow chart in FIG. 6 isimplemented by the system control circuit 50 by loading a program fromthe non-volatile memory 56 on the system memory 52 and executing it.

Referring to FIG. 6, in step S601, the system control circuit 50 clearsthe display of the button icons 501 to 503, and the icons 504 to 507 onthe screen illustrated in FIG. 5. In step S602, the system controlcircuit 50 executes image shooting standby processing, such as AFprocessing or AE processing. If an in-focus state is achieved, thesystem control circuit 50 executes control for displaying an in-focusframe which is displayed superposedly on the through-the-lens image 500.In step S603, the system control circuit 50 determines whether the SW2is ON. If it is determined that the SW2 is ON (Yes in step S603), thenthe processing advances to step S605. On the other hand, if it isdetermined that the SW2 is not ON (No in step S603), then the processingadvances to step S604.

In step S604, the system control circuit 50 determines whether the SW1is still ON. If it is determined that the SW1 is still ON (Yes in stepS604), then the processing returns to step S603. On the other hand, ifit is determined that the SW1 is not ON (No in step S604), then theprocessing advances to step S607. In step S607, the system controlcircuit 50 displays the image shooting standby screen. The processing instep S607 is similar to the processing in step S401 described above withreference to FIG. 4A. More specifically, in step S607, the systemcontrol circuit 50 executes control for displaying the button icons 501to 503, and the icons 504 to 507 again which have been eliminated fromthe display in step S601.

On the other hand, if it is determined that the SW2 is ON (Yes in stepS603), then the processing advances to step S605. In step S605, thesystem control circuit 50 executes image taking processing (an actualimage shooting operation) including exposure and image processing. Instep S606, the system control circuit 50 records the image taken by theactual image shooting operation on the recording medium 200 as a file.In step S607, the system control circuit 50 displays the image shootingstandby screen. Then, the processing returns to step S402 in FIG. 4A.

Now, an example of a method will be described in detail below fordetermining whether the user has touched the touch panel at a differentposition with a different finger while continuously touching the buttonicon 501 which is executed in step S423 in FIG. 4B (the processing thatimplements the multi point touching determination unit) with referenceto FIGS. 8A through 8C.

With respect to the type of a device of the touch panel, a capacitancetype device capable of executing multi-point detection cansimultaneously detect a touching position on the button icon 501 (afirst touching position) and another touching position (a secondtouching position) by the touching operations in step S423 in FIG. 4B.Accordingly, in the above described capacitance device, when thetouching position on the button icon 501 and the touch-down operation ona different position are simultaneously detected, the system controlcircuit 50 can determine that the user has touched the touch panel atthe different other position with the different finger whilecontinuously touching the button icon 501 without executing a specialmethod.

On the other hand, with respect to the type of a device of the touchpanel, a resistance film type device has been widely used which iscapable of detecting only a single touching position and not capable ofexecuting multi-point detection. If the resistance film type devicedescribed above is used, the system control circuit 50 determineswhether the user has touched the touch panel at a different positionoutside the area of the button icon 501 with the different finger whiletouching the button icon 501 in the following manner.

First, an example of a method for detecting a touching position on theresistance film type touch panel will be described in detail below. Inthe resistance film type touch panel, when the user has touched thetouch panel at a single position only as illustrated in FIGS. 8A and 8B,a resistance value on each of an X-axis and a Y-axis which are set onthe display unit 28 is detected. The touching position is identifiedaccording to the detected resistance values.

In the example illustrated in FIG. 8A, the resistance value on each ofthe X-axis and the Y-axis is detected for a point 801 as the touchingposition. The system control circuit 50 acquires an X coordinate and a Ycoordinate on the display unit 28 and identifies the touching position.Similarly, in the example illustrated in FIG. 8B, the system controlcircuit 50 acquires an X coordinate and a Y coordinate of a point 802 asthe touching position on the display unit 28. The system control circuit50 identifies the touching position according to the acquired X and Ycoordinates of the touching position 802.

However, in the case of the resistance film type touch panel, if theuser has simultaneously touched the touch panel at a plurality ofpoints, the resistance film type touch panel detects the resistancevalue on both of the X- and Y-axes for a midpoint of the plurality oftouching points only. For example, when the user has touched the touchpanel simultaneously at points 804 and 805 on the display unit 28, theresistance film type touch panel detects the resistance values for asingle point 806 only which is the midpoint between the points 804 and805. Accordingly, in this case, touching operations simultaneouslyexecuted at a plurality of touching positions cannot be detected.However, by utilizing the characteristic such that the resistance valuesof the midpoint of two different simultaneously touched points aredetected, if the user has touched the touch panel at a first point andthe touching position thereof is acquired, the system control circuit 50can determine whether the user has touched the touch panel at a secondpoint while the touching of the first point is continued according tothe acquired touching position.

Now, an example of a method of the determination processing executed instep S423 in FIG. 4B will be described in detail below. In the exampleillustrated in FIG. 8C, an area 803 indicates the area of the buttonicon 501. A center point 808 indicates the center point of the displayunit 28. An upper-right area 807 indicates an area existing in anupper-right area of the display unit 28 from the center point 808 (anarea including points whose X coordinate exists in the right-hand areaof the center point 808 and whose Y coordinate exists in the upper-handarea of the center point 808). In this state, in most cases, themidpoint of a point existing within the area 803 and a different otherarbitrary point existing in another area is generally included in theupper-right area 807. On the other hand, a point that does not existwithin the upper-right area 807 can be considered not to be the midpointof a single point included in the area 803 and another arbitrary pointincluded in another area.

Accordingly, in step S423 of the present invention, if a touchingposition existing within the upper-right area 807 is detected after astate in which a single point included in the area 803 was detected asthe touching position without detecting the touch-up operation, then thesystem control circuit 50 determines that the user has touched the touchpanel with the finger other than the finger touching the button icon 501simultaneously as touching the button icon 501.

For example, when a touching operation at the point 806 has beendetected after a touching operation at the point 804 is detected withoutdetecting the touch-up operation in the example illustrated in FIG. 8C,it can be estimated that the user has touched the point 805, which is apoint of point symmetry with the point 804 around the point 806,simultaneously as touching the point 804. Accordingly, the systemcontrol circuit 50 displays the warning message 2 which indicates thatthe user cannot execute the touch AF function assigned at the positionof the point 805. By executing the method described above, the presentexemplary embodiment can detect simultaneously executed touchingoperations at a plurality of positions if the resistance film type touchpanel is used.

As described above, if the user has touched the touch panel in aspecific area thereof (i.e., on the button icon 501) continuously for apredetermined time period or longer, the exemplary embodiment of thepresent invention disables the function assigned to the touched area anddoes not execute the function corresponding to the touched area even ifthe user executes the touch-up operation after that. In this case, thesystem control circuit 50 disables the function of the touched area onlytemporarily. As described above with reference to the flow chart inFIGS. 4A and 4B, the user can execute the function of the touched areaby performing the touch-up operation by touching the touch panel againwithin a predetermined time period after the touch-up operation. Withthe above described configuration, the present exemplary embodiment canprevent execution of a function if the user unintentionally touches thetouch panel. Accordingly, the present exemplary embodiment can suppressan operation error.

Further, the present exemplary embodiment disables the function onlytemporarily before the user executes the touch-up operation.Accordingly, it is only necessary for the user to tap the button icon501 again if the user desires to execute the function assigned to thebutton icon 501. Therefore, it is not necessary for the user to executea particular operation for releasing the function disabled state.Accordingly, the present exemplary embodiment can prevent an operationerror without degrading the operability.

Further, according to the exemplary embodiment of the present invention,a button icon that is capable of reducing an operation error, such asthe button icon 501 described above, can be provided on the touch panelat a position that the user may easily and unintentionally touch.Accordingly, the present exemplary embodiment can reduce restriction ofa layout of touching operation members of the touch panel.

In the example illustrated in FIGS. 4A and 4B, the system controlcircuit 50 temporarily disables the button icon (the specific area) 501only, among the plurality of button icons, if the user touches the samefor the predetermined time period or longer. Button icons other than thebutton icon 501, such as the button icon 502 (the other area), areenabled regardless of the time period of continuous touch-on state. Thebutton icon 501 is provided at a position the closest to a vertex (anupper-right vertex of the display unit 28) nearest to the shutter button61 among button icons displayed on the display unit 28. In most cases,the user may hold the digital camera 100, which includes a shutterbutton, in the manner described above with reference to FIG. 3.Therefore, the user may unintentionally touch the touch panel at avertex of the display unit 28 near the shutter button 61. On thecontrary, the user may not often touch the touch panel at a positiondistant from the vertex near the shutter button 61. Therefore, if atouching operation at a position on the touch panel distant from theshutter button 61 has been detected, it is likely that the user hastouched the touch panel at the position intentionally. Therefore, it isuseful if the system control circuit 50 disables only a button iconprovided at a position that is the nearest from a vertex of the displayunit 28 from the shutter button 61 among a plurality of button icons ifa continuous touching operation for a predetermined time period orlonger has been executed. Accordingly, the present exemplary embodimentcan appropriately distinguish between unintentional touching by the userand an intentional touching operation by the user.

In the example illustrated in FIGS. 4A and 4B, the system controlcircuit 50 disables the button icon 501 only if the user has touched thebutton icon for a predetermined time period or longer. However, thepresent invention is not limited to this. The number of button iconsdisabled by the continuous touching for the predetermined time period orlonger is not limited to one.

In other words, the system control circuit 50 may disable some of or allof a plurality of button icons if continuous touching by the user forthe predetermined time period or longer is detected. For example, asillustrated in FIG. 3, the user may touch the touch panel at a positionof the display unit 28 whose Y coordinate is close to the shutter button61 with the cushion portion of the right-hand thumb in the lower portionof the display unit 28. Accordingly, the system control circuit 50 maydisable a plurality of button icons whose Y coordinate is close to theshutter button 61 if the button icon is continuously touched by the userfor the predetermined time period or longer. Further, the system controlcircuit 50 may disable the plurality of button icons at different timeperiods of continuous touching according to the positions at which thebutton icons are provided. In this case, considering the difference ofprobability of unintentional touching according to the position of thebutton icons, it is useful to shorten the time period of continuoustouching (threshold value), according to which the functioncorresponding to the button icon is disabled as the distance of theposition from the shutter button 61 becomes less.

For example, it is assumed that the system control circuit 50temporarily disables the button icon 502 when continuous touching by theuser for the predetermined time period or longer is detected.

In this case, if it is determined that the user has touched the touchpanel on the button icon 502 (a second area) (Yes in step S403 in FIG.4A), then the system control circuit 50 starts the timer and counts thelength of the time period in which the button icon 502 is in thetouch-on state. This method implements a second time counting unitaccording to the present exemplary embodiment. Then, the system controlcircuit 50 determines whether the length of the time period in which thebutton icon 502 is in the touch-on state has reached or become longerthan a second time period which is longer than the length of time periodof continuous touching (the predetermined time period used in step S411)that is the criterion of disabling the execution of the function of thebutton icon 501 (the specific area).

If it is determined that the touch-up operation from the position of thebutton icon 502 is detected in step S406 and the length of the timeperiod of continuous touching at the position of the button icon 502which is counted by using the timer has not reached the second timeperiod, then the system control circuit 50 executes the functionassigned to the button icon 502. On the other hand, if it is determinedthat the touch-up operation from the position of the button icon 502 isdetected in step S406 and the length of the time period of continuoustouching at the position of the button icon 502 which is counted byusing the timer has reached the second time period, then the systemcontrol circuit 50 does not execute the function assigned to the buttonicon 502.

In the present exemplary embodiment, the second time period is setlonger than the predetermined time period used in step S411 (FIG. 4A)because the button icon 502 (the second area) is more distant from thevertex of the display unit 28 that is the closest to the shutter button61 (i.e., the upper-right vertex of the display unit 28) than the buttonicon 501 (the specific area). As described above, in the presentexemplary embodiment, if the distance of a touching position from theshutter button 61 is short, it is determined that the possibility ofoccurrence of erroneous touching on the touch panel becomes higher.Therefore, it is useful to shorten the time period of continuoustouching, according to which the function corresponding to the buttonicon is disabled, as the distance of the position from the shutterbutton 61 becomes less. Accordingly, the system control circuit 50 doesnot execute the function of the corresponding button icon unless theuser executes a specific intentional operation, and the presentexemplary embodiment can prevent an operation error.

As a possibility of the operation error, if a user carries the digitalcamera 100 in a bag or puts the digital camera 100 with the display unit28 facing down, in which the touch panel is provided, an object maytouch the touch panel against the intention of the user. The presentinvention is useful in preventing the operation error that may otherwiseoccur due to the above described touching on the touch panel. Once theabove described unintentional touching on the touch panel occurs, it islikely that the touching continues for a relatively long time period. Inthis case, according to the present invention that temporarily disablestouching that continues for a predetermined time period or longer, theoperation error that may otherwise occur due to unintentional touchingcan be prevented. In this case, since the position of the button icon onthe surface of the display unit 28 does not relate to the probability ofoccurrence of the operation error, the system control circuit 50 maytemporarily disable the functions of all the button icons when touchingcontinues for the predetermined time period or longer.

The processing executed in the image shooting mode is described abovewith reference to FIGS. 4A and 4B. On the other hand, in the imagereproduction mode, different from the image shooting mode, a button iconprovided at the same position as the position of the button icon 501 ora button icon provided in a state at least a part thereof is overlappedwith the area of the button icon 501 may be enabled regardless of thelength of the time period of the touching. This is because in the imagereproduction processing, different from the case of the image shootingmode, it is likely that the user does not hold the digital camera 100 inthe manner in which the finger of the user touches the shutter button 61as illustrated in FIG. 3. Therefore, a button icon whose correspondingfunction is to be disabled by continuous touching for a predeterminedtime period or longer is not provided for the image reproduction mode.Alternatively, considering the way of holding of the digital camera 100by the user during the image reproduction mode, a button icon whosecorresponding function is to be disabled by continuous touching for thepredetermined time period or longer may be provided at a positiondifferent from the position of the button icons for the image shootingmode.

It is also useful if the digital camera 100 includes an attitudedetection sensor. An attitude detection sensor refers to a sensorcapable of detecting an attitude of the digital camera 100 in relationto the direction of gravity. The attitude detection sensor includes asensor, such as an acceleration sensor or a vertical-horizontal deviceposition sensor.

When the attitude detection sensor detects that the front face of thedigital camera 100 is horizontally oriented (a first attitude), it islikely that the digital camera 100 is held by the user in the mannerdescribed above with reference to FIG. 3. On the other hand, when theattitude detection sensor detects that the front face of the digitalcamera 100 is vertically oriented (a second attitude), it is likely thatthe digital camera 100 is held in a manner different from the mannerdescribed above with reference to FIG. 3. In this case, it is likelythat the user touches the touch panel at a position different from theposition illustrated in FIG. 3. Accordingly, when the attitude detectionsensor detects that the front face of the digital camera 100 isvertically oriented, it is useful that a button icon provided at aposition different from the button icon which is provided when theattitude detection sensor detects that the front face of the digitalcamera 100 is horizontally oriented, may be temporarily disabled upondetection of continuous touching for a predetermined time period orlonger.

More specifically, when the attitude detection sensor detects that thedigital camera 100 is horizontally oriented, it is useful if the buttonicon 501 is set as the button icon to be disabled if continuous touchingfor the predetermined time period or longer is detected as describedabove with reference to FIGS. 4A and 4B. In addition, button icons otherthan the button icon 501 are kept enabled regardless of the length ofthe time period of the continued touch-on operation. On the other hand,when the attitude detection sensor detects that the digital camera 100is vertically oriented, it is useful if a button icon other than thebutton icon 501 (i.e., the button icon 503, for example) is set as thebutton icon to be temporarily disabled if continuous touching thereonfor the predetermined time period or longer is detected. In addition,the button icons other than the button icon 503, including the buttonicon 501, are enabled regardless of the length of the time period of thecontinued touch-on operation. With the above described configuration,the present exemplary embodiment can securely prevent an operation erroraccording to the attitude of the digital camera 100.

The type of the touch panel implemented by the present invention is notlimited to a specific type. More specifically, any touch panel capableof detecting an operation of touching the display unit can be used asthe touch panel according to an exemplary embodiment of the presentinvention. The type of the touch panel that can be employed in thepresent invention includes a surface acoustic wave type touch panel, aninfrared-ray type touch panel, or an electromagnetic induction typetouch panel in addition to the resistance film type touch panel and thecapacitance type touch panel described above.

The above described exemplary embodiment is implemented by an imagepickup apparatus. However, the present invention can be implemented byany apparatus or device other than the image pickup apparatus thatcontrols a display device including a touch panel, such as a cellularphone, a personal digital assistant (PDA), a music player, an imageviewer, a videogame machine, a printing apparatus, or a car navigationdevice. If the present invention is implemented by an apparatus ordevice other than the image pickup apparatus, it is useful, consideringthe way of holding the apparatus or device or the state of use thereof,if a button icon is disabled at a specific appropriate timing accordingto the position at which each of a plurality of button icons isprovided.

If the present invention is implemented by an apparatus or device otherthan the image pickup apparatus which does not include a shutter button,the user may unintentionally touch the touch panel with the hand thatholds the apparatus or device at a position close to a gripping(holding) portion of the apparatus or device. Accordingly, it is usefulif only a button icon provided on the display unit at a position closeto the gripping portion is disabled when continuous touching for thepredetermined time period or longer is detected. Alternatively, it isalso useful if some button icons provided on the display unit at aposition close to the gripping portion are disabled if continuoustouching for the predetermined time period or longer is detected. Ifdifferent length of time period of continuous touching is set for eachbutton icon, the length of time period of continuous touching fordisabling the function thereof may be set short for a button iconprovided at a position close to the gripping portion.

The exemplary embodiments of the present invention are described above.However, the present invention is not limited to the above describedexemplary embodiments of the present invention. More specifically,various other embodiments can be included in the scope of the presentinvention and implement the present invention. Furthermore, acombination of a plurality of the above described exemplary embodimentsof the present invention can implement the present invention.

The above described control of the entire digital camera 100 can beimplemented by single hardware or can be shared by a plurality ofhardware devices.

The present invention can also be achieved by providing a system or anapparatus with a storage medium storing program code of softwareimplementing the functions of the exemplary embodiments and by readingand executing the program code stored in the storage medium with acomputer of the system or the apparatus (a central processing unit (CPU)or a micro processing unit (MPU)). In this case, the program codeitself, which is read from the storage medium, implements the functionsof the embodiments described above, and accordingly, the storage mediumstoring the program code constitutes the present invention.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures, and functions.

1. An information processing apparatus comprising a memory and at leastone processor, the at least one processor operating as: a touchingdetection unit configured to detect at least one touching operation fortouching a display unit, and a respective or corresponding touch-upoperation for discontinuing the at least one touching operation on thedisplay unit; a display control unit configured to control the displayunit to display a first display object in a first area of the displayunit and to display a second display object in a second area of thedisplay unit which is different from the first area; a time countingunit configured to count a time period of the at least one touchingoperation on at least one of the first display object and the seconddisplay object of the display unit, the at least one touching operationbeing continuous from a beginning to an end of the at least one touchingoperation; and a system control unit configured: (a) to execute a firstfunction, which changes a mode or a setting of the informationprocessing apparatus, assigned to the first display object based on thetouching detection unit detecting the respective or correspondingtouch-up operation from the first display object on which a firsttouching operation of the at least one touching operation has beendetected before the time period of the first touching operation on thefirst display object counted by the time counting unit has reached atime period threshold; (b) to change an appearance of the first displayobject from a first appearance to a second appearance in response to thetime period of the first touching operation on the first display objectcounted by the time counting unit having reached the time periodthreshold after the first touching operation on the first display objecthas been detected by the touching detection unit; (c) to execute asecond function, which changes a mode or a setting of the informationprocessing apparatus, assigned to the second display object, based onthe touching detection unit detecting the respective or correspondingtouch-up operation from the second display object on which a secondtouching operation of the at least one touching operation has beendetected regardless of whether the time period of the second touchingoperation on the second display object is longer than the time periodthreshold or not; and (d) not to execute the first function assigned tothe first display object based on the touching detection unit detectingthe respective or corresponding touch-up operation from the firstdisplay object on which the first touching operation has been detectedafter the time period of the first touching operation on the firstdisplay object has reached the time period threshold.
 2. The informationprocessing apparatus according to claim 1, wherein the system controlunit is configured to execute the second function assigned to the seconddisplay object, based on the touching detection unit detecting thetouch-up operation from the second display object on which the touchingoperation has been detected, and in response to the time period of thetouching operation on the second display object being shorter than thetime period threshold.
 3. The information processing apparatus accordingto claim 1, wherein the at least one processor further functions as asecond time counting unit configured to count a second time period ofthe touching operation on the second display object, and wherein thesystem control unit is configured to perform a control: (i), based onthe touching detection unit detecting the touch-up operation from thesecond display object on which the touching operation has been detectedand based on the second time period counted by the second time countingunit having not reached the time period threshold, to execute the secondfunction assigned to the second display object, or (ii) based on thetouching detection unit detecting the touch-up operation from the seconddisplay object on which the touching operation has been detected andbased on the second time period counted by the second time counting unithaving reached the second time period, not to execute second functionassigned to the second display object based on a detection of thetouch-up operation.
 4. The information processing apparatus according toclaim 1, wherein the system control unit is configured to perform acontrol: (i) in response to the information processing apparatus beingin a specific mode, based on the touching detection unit detecting thetouch-up operation from the first display object on which the touchingoperation has been detected, and based on the time period counted by thetime counting unit having reached the time period threshold, not toexecute the first function assigned to the first display object based ondetection of the touch-up operation, or (ii) in response to theinformation processing apparatus being in a mode other than the specificmode and based on the touching detection unit detecting the touch-upoperation from the first display object on which the touching operationhas been detected, to execute the first function assigned to the firstdisplay object regardless of the time period of the touching operationon the first display object.
 5. The information processing apparatusaccording to claim 4, further comprising: an imaging unit; and a modeshifting unit configured to shift an operation mode of the informationprocessing apparatus to one mode among a plurality of modes at leastincluding an image shooting mode and an image reproduction mode, whereinthe specific mode is the image shooting mode.
 6. The informationprocessing apparatus according to claim 1, further comprising: animaging unit; and a shutter operation member configured to receive auser instruction for taking an image given by the imaging unit, whereinthe first display object is a button icon displayed on the display unitat a position that is the closest to a vertex of the display unit thatis the closest from the shutter operation member.
 7. The informationprocessing apparatus according to claim 1, further comprising: animaging unit; and a shutter operation member configured to receive auser instruction for taking an image given by the imaging unit, whereinthe first display object is a button icon displayed on the display unitat a position that is closer to a vertex of the display unit that is theclosest from the shutter operation member than a position of the seconddisplay object.
 8. The information processing apparatus according toclaim 3, further comprising: a imaging unit; and a shutter operationmember configured to receive a user instruction for taking an imagegiven by the second imaging unit, wherein the specific area is an areaof a button icon displayed on the display unit at a position that iscloser to a vertex of the display unit that is the closest from theshutter operation member than a position of the second area.
 9. Theinformation processing apparatus according to claim 1, wherein thedisplay control unit is configured, in response to the time periodcounted by the time counting unit having reached the time periodthreshold, to perform a control to display a first warning messageindicating that the first display object has been touched on the displayunit.
 10. The information processing apparatus according to claim 9,wherein the at least one processor further operates as a multi-pointtouching determination unit configured to determine whether a thirddisplay object different from the first display object has been touchedsimultaneously with the touching operation on the first display object,and wherein the display control unit is configured, in response to themulti-point touching determination unit determining that the thirddisplay object has been touched simultaneously with the touchingoperation on the first display object, to display a second warningmessage indicating that an action instructed by the touching operationcannot be executed on the display unit.
 11. The information processingapparatus according to claim 10, wherein the multi-point touchingdetermination unit is configured, in response to the touching operationon the display unit within a range in the display unit having beendetected without detecting the touch-up operation after the touchingoperation on the first display object has been detected, to determinethat a position included in the third display object has been touchedsimultaneously with the touching operation on the first display object.12. The information processing apparatus according to claim 11, whereinthe second warning message indicates that a function assigned to a firstposition based on the touching operation occurring within the first areaaround a second position included in the range cannot be executed. 13.The information processing apparatus according to claim 1, furthercomprising an attitude detection unit configured to detect an attitudeof the information processing apparatus, wherein a position on thedisplay unit is set as the first display object according to theattitude detected by the attitude detection unit.
 14. The informationprocessing apparatus according to claim 1, wherein the first displayobject is a button icon displayed at a position on the display unit thatis closest from a position of a gripping portion for holding theinformation processing apparatus.
 15. The information processingapparatus according to claim 1, wherein the first area is an upper rightarea of the display unit.
 16. The information processing apparatusaccording to claim 1, wherein the display control unit is furtherconfigured to control the display unit to display a warning messagecorresponding to the first display object.
 17. The informationprocessing apparatus according to claim 1, wherein the display controlunit is further configured to control the display unit to display anicon corresponding to the first display object.
 18. A method forcontrolling an information processing apparatus, the method comprising:detecting at least one touching operation for touching a display unit;displaying a first display object in a first area of the display unitand displaying a second display object in a second area of the displayunit which is different from the first area; counting a time period ofthe at least one touching operation on at least one of the first displayobject and the second display object of the display unit, the at leastone touching operation being continuous from a beginning to an end ofthe at least one touching operation; detecting a respective orcorresponding touch-up operation for discontinuing the at least onetouching operation on the display unit; executing a first function,which changes a mode or a setting of the information processingapparatus, assigned to the first display object based on detection ofthe respective or corresponding touch-up operation from the firstdisplay object on which a first touching operation of the at least onetouching operation has been detected before the counted time period ofthe first touching operation on the first display object has reached atime period threshold; changing an appearance of the first displayobject from a first appearance to a second appearance in response to thecounted time period of the first touching operation on the first displayobject having reached the time period threshold after the first touchingoperation on the first display object has been detected by thedetecting; executing a second function, which changes a mode or asetting of the information processing apparatus, assigned to the seconddisplay object, based on detection of the respective or correspondingtouch-up operation from the second display object on which a secondtouching operation of the at least one touching operation has beendetected regardless of whether the counted time period of the secondtouching operation on the second display object is longer than the timeperiod threshold or not; and not executing the first function assignedto the first display object based on the detection of the respective orcorresponding touch-up operation from the first display object on whichthe first touching operation has been detected after the counted timeperiod of the first touching operation on the first display object hasreached the time period threshold.
 19. The method for controlling theinformation processing apparatus according to claim 18, wherein thesecond function assigned to the second display object is also executed,in response to the detection of the touch-up operation from the seconddisplay object on which the touching operation has been detected, andregardless of whether the counted time period of the touching operationon the second display object is shorter than the time period threshold.20. An information processing apparatus comprising at least oneprocessor, the at least one processor operating as: a touching detectionunit configured to detect at least one touching operation for touching adisplay unit, and a respective or corresponding touch-up operation fordiscontinuing the at least one touching operation on the display unit; adisplay control unit configured to control the display unit to display afirst display object in a first area of the display unit and to displaya second display object in a second area of the display unit which isdifferent from the first area; a time counting unit configured to counta time period of the at least one touching operation on at least one ofthe first display object and the second display object of the displayunit, the at least one touching operation being continuous from abeginning to an end of the at least one touching operation; and a systemcontrol unit configured: (a) to execute a first function, which changesa mode or a setting of the information processing apparatus, assigned tothe first display object based on the touching detection unit detectingthe respective or corresponding touch-up operation from the firstdisplay object on which a first touching operation of the at least onetouching operation has been detected before the time period of the firsttouching operation on the first display object counted by the timecounting unit has reached a time period threshold; (b) to change anappearance of the first display object from a first appearance to asecond appearance in response to the time period of the first touchingoperation on the first display object counted by the time counting unithaving reached the time period threshold after the first touchingoperation on the first display object has been detected by the touchingdetection unit; (c) to execute a second function, which changes a modeor a setting of the information processing apparatus, assigned to thesecond display object, based on the touching detection unit detectingthe respective or corresponding touch-up operation from the seconddisplay object on which a second touching operation of the at least onetouching operation has been detected regardless of whether the timeperiod of the second touching operation on the second display object islonger than the time period threshold or not; and (d) not to execute thefirst function assigned to the first display object based on thetouching detection unit detecting the respective or correspondingtouch-up operation from the first display object on which the firsttouching operation has been detected after the time period of the firsttouching operation on the first display object has reached the timeperiod threshold.
 21. A non-transitory computer-readable storage mediumstoring instructions which cause a computer to execute a method forcontrolling an information processing apparatus, the method comprising:detecting at least one touching operation for touching a display unit;displaying a first display object in a first area of the display unitand displaying a second display object in a second area of the displayunit which is different from the first area; counting a time period ofthe at least one touching operation on at least one of the first displayobject and the second display object of the display unit, the at leastone touching operation being continuous from a beginning to an end ofthe at least one touching operation; detecting a respective orcorresponding touch-up operation for discontinuing the at least onetouching operation for touching the display unit; executing a firstfunction, which changes a mode or a setting of the informationprocessing apparatus, assigned to the first display object based ondetection of the respective or corresponding touch-up operation from thefirst display object on which a first touching operation of the at leastone touching operation has been detected before the counted time periodof the first touching operation on the first display object has reacheda time period threshold; changing an appearance of the first displayobject from a first appearance to a second appearance in response to thecounted time period of the first touching operation on the first displayobject having reached the time period threshold after the first touchingoperation on the first display object has been detected by thedetecting; executing a second function, which changes a mode or asetting of the information processing apparatus, assigned to the seconddisplay object, based on detection of the respective or correspondingtouch-up operation from the second display object on which a secondtouching operation of the at least one touching operation has beendetected regardless of whether the counted time period of the secondtouching operation on the second display object is longer than the timeperiod threshold or not; and not executing the first function assignedto the first display object based on the detection of the respective orcorresponding touch-up operation from the first display object on whichthe first touching operation has been detected after the counted timeperiod of the first touching operation on the first display object hasreached the time period threshold.
 22. The non-transitorycomputer-readable storage medium storing instructions which cause acomputer to execute a method for controlling an information processingapparatus according to claim 21, wherein the second function assigned tothe second display object is also executed, in response to the detectionof the touch-up operation from the second display object on which thetouching operation has been detected, and regardless of whether thecounted time period of the touching operation on the second displayobject is shorter than the time period threshold.